Method of optimizing tension in applying leg elastics

ABSTRACT

A method of applying leg elastics to absorbent garments involves varying the number and position of feed nips and idler rolls and optimizing the tension between multiple elastic members. The elastic members are bonded to a substrate with variable tension. More particularly, higher tension is provided in the areas of the garment where greater gasketing pressure is required, while lower tension is provided in areas where greater comfort is desired and high gasketing pressure is not needed. Furthermore, each elastic member may vary in degrees of tension from the other elastic members. The resulting garments have optimized comfort, fit and containment about the leg openings.

FIELD OF THE INVENTION

This invention is directed to a method of optimizing tensiondistribution in the application of leg elastics to a garment. The methodinvolves varying the number and position of feed nips and idler rollsand varying elongation of the elastic members.

BACKGROUND OF THE INVENTION

Pant-like absorbent garments, such as adult incontinence wear, infantand children's diapers, swim wear and training pants, typically includea pair of leg openings having an elastic portion around each legopening. The elastic portions are intended to fit snugly around awearer's legs to prevent leakage from the garment. However, more tensionis required in certain areas around the leg, such as in the crotch area,than in other areas around the leg, such as in the area away from thecrotch.

Various technologies are known for applying leg elastics to sucharticles. For example, some technologies involve increasing spacingbetween elastic members at the crotch area around each leg opening. Thistype of spacing is the normal process fallout due to the correspondencebetween the angle of application and the spacing between the elasticmembers. More particularly, when the elastic members are applied to agarment in a machine direction, variations in the angle of applicationresult in variations in spacing. When a device used to apply the elasticmembers aligns the elastic members in the crotch area in a rowsubstantially perpendicular to the machine direction, as the elasticmembers are guided away from the crotch area, the angle between the rowand the machine direction is closer to 0°, thereby resulting in widerspacing in the crotch area and narrower spacing in the area away fromthe crotch. Other technologies boast consistent spacing between elasticmembers around the entire leg opening. Some of the technologiesmentioned, and others, include consistent tension among elastic membersaround the entire leg opening.

There is a need or desire for a process for optimizing gasketingpressure around the leg openings of pant-like absorbent garments toprovide enhanced comfort, fit and containment about the leg openings ofsuch garments.

SUMMARY OF THE INVENTION

It has been found that variations in tension among elastic members causevariations in gasketing pressure and can be optimized to provideenhanced comfort, fit and containment about the leg openings.

The present invention is directed to a method of applying leg elasticsto pant-like absorbent garments using variable tension among the elasticmembers. The result is a garment with regions of customized highertension for higher gasketing and regions of lower tension for greatercomfort.

Apparatus that can be used for carrying out the invention includes apivot arm that can be aligned substantially parallel or perpendicular toa substrate, or anywhere in between, with respect to the machinedirection. The pivot arm can pivot from side to side across thesubstrate as the substrate travels through a pair of nip rolls in themachine direction. The pivot arm guides the elastic members as theelastic members are fed through a feed nip. The placement of the feednip for the elastic members results in increased tension as the pivotarm moves the elastic members away from the feed nip. Conversely, as thepivot arm moves the elastic members toward the feed nip, the tension isreduced. The tension can be controlled in this manner such that highertension can be applied in the desired area of the pant and lower tensioncan be applied in areas of the pant where less gasketing pressure isrequired.

In another embodiment of the invention, separate feed nips are providedfor each elastic member. As a result, the tension profile of eachelastic member can be different. The placement of the feed nip relativeto the corresponding elastic guide at any given pivot arm positiondetermines the tension profile in the elastic member, even if the feednips are driven at the same constant speed.

In a further embodiment of the invention, idler rolls are located invarious positions. As a result, the tension profile of each elasticmember can be different. More specifically, a strategically placedelastic feed nip and a corresponding idler roll change the stretchingamount of each individual elastic member such that a different and evenopposite tension gradient can be placed on members that are side by sidein the product composite.

In yet another embodiment of the invention, an idler roll on a shaftconnected to a rotating wheel is used to control elongation of theelastic members. Virtually any type of tension profile can be createdwith this method.

With the foregoing in mind, it is a feature and advantage of theinvention to provide a method of applying leg elastics to an absorbentgarment resulting in optimized performance of the leg elastics in termsof comfort, fit and containment.

It is another feature and advantage of the invention to provide a methodof tailoring leg elastic tension in an absorbent garment to fit awearer's body.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side perspective view of an absorbent garment;

FIG. 2 is a plan view of the absorbent garment of FIG. 1 in a partiallydisassembled, stretched flat state, and showing the surface of thearticle that faces the wearer when the article is worn, and withportions cut away to show the underlying features;

FIG. 3 is a top plan view of apparatus used for applying leg elastics toan absorbent garment according to one embodiment of the invention;

FIG. 4 is a top plan view of apparatus used for applying leg elastics toan absorbent garment according to a second embodiment of the invention;

FIG. 5 is a top plan view of apparatus used for applying leg elastics toan absorbent garment according to a third embodiment of the invention;

FIG. 6 is a side view of apparatus used for varying elongation ofelastic members;

FIG. 7 is a side view of any of FIGS. 3-5; and

FIG. 8 is an alternative side view of any of FIGS. 3-5.

DEFINITIONS

Within the context of this specification, each term or phrase below willinclude the following meaning or meanings. “Bonded” refers to thejoining, adhering, connecting, attaching, or the like, of two elements.Two elements will be considered to be bonded together when they arebonded directly to one another or indirectly to one another, such aswhen each is directly bonded to intermediate elements.

“Connected” refers to the joining, adhering, bonding, attaching, or thelike, of two elements. Two elements will be considered to be connectedtogether when they are connected directly to one another or indirectlyto one another, such as when each is directly connected to intermediateelements.

“Disposable” refers to articles which are designed to be discarded aftera limited use rather than being laundered or otherwise restored forreuse.

“Disposed,” “disposed on,” and variations thereof are intended to meanthat one element can be integral with another element, or that oneelement can be a separate structure bonded to or placed with or placednear another element.

“Elastic,” “elasticized” and “elasticity” mean that property of amaterial or composite by virtue of which it tends to recover itsoriginal size and shape after removal of a force causing a deformation.

“Elastomeric” refers to a material or composite which can be elongatedby at least 25 percent of its relaxed length and which will recover,upon release of the applied force, at least 10 percent of itselongation. It is generally preferred that the elastomeric material orcomposite be capable of being elongated by at least 100 percent, morepreferably by at least 300 percent, of its relaxed length and recover,upon release of an applied force, at least 50 percent of its elongation.

“Film” refers to a thermoplastic film made using a film extrusion and/orfoaming process, such as a cast film or blown film extrusion process.The term includes apertured films, slit films, and other porous filmswhich constitute liquid transfer films, as well as films which do nottransfer liquid. The term also includes film-like materials that existas open-celled foams.

“Force” includes a physical influence exerted by one body on anotherwhich produces acceleration of bodies that are free to move anddeformation or separation of bodies that are not free to move.

“Hydrophilic” describes fibers or the surfaces of fibers which arewetted by the aqueous liquids in contact with the fibers. The degree ofwetting of the materials can, in turn, be described in terms of thecontact angles and the surface tensions of the liquids and materialsinvolved. Equipment and techniques suitable for measuring thewettability of particular fiber materials or blends of fiber materialscan be provided by a Cahn SFA-222 Surface Force Analyzer System, or asubstantially equivalent system. When measured with this system, fibershaving contact angles less than 90° are designated “wettable” orhydrophilic, while fibers having contact angles greater than 90° aredesignated “nonwettable” or hydrophobic.

“Layer” when used in the singular can have the dual meaning of a singleelement or a plurality of elements.

“Leg elastic” includes elastic bands, strands, ribbons, filaments,filament bunches and the like, which are adjacent to a garment openingthat receives a wearer's leg.

“Liquid impermeable,” when used in describing a layer or multi-layerlaminate, means that a liquid, such as urine, will not pass through thelayer or laminate, under ordinary use conditions, in a directiongenerally perpendicular to the plane of the layer or laminate at thepoint of liquid contact. Liquid, or urine, may spread or be transportedparallel to the plane of the liquid impermeable layer or laminate, butthis is not considered to be within the meaning of “liquid impermeable”when used herein.

“Liquid-permeable material” or “liquid water-permeable material” refersto a material present in one or more layers, such as a film, nonwovenfabric, or open-celled foam, which is porous, and which is waterpermeable due to the flow of water and other aqueous liquids through thepores. The pores in the film or foam, or spaces between fibers orfilaments in a nonwoven web, are large enough and frequent enough topermit leakage and flow of liquid water through the material.

“Longitudinal” and “transverse” have their customary meaning, asindicated by the longitudinal and transverse axes depicted in FIG. 2.The longitudinal axis lies in the plane of the article and is generallyparallel to a vertical plane that bisects a standing wearer into leftand right body halves when the article is worn. The transverse axis liesin the plane of the article generally perpendicular to the longitudinalaxis. The article as illustrated is longer in the longitudinal directionthan in the transverse direction.

“Meltblown fibers” means fibers formed by extruding a moltenthermoplastic material through a plurality of fine, usually circular,die capillaries as molten threads or filaments into converging highvelocity heated gas (e.g., air) streams which attenuate the filaments ofmolten thermoplastic material to reduce their diameter, which may be tomicrofiber diameter. Thereafter, the meltblown fibers are carried by thehigh velocity gas stream and are deposited on a collecting surface toform a web of randomly dispersed meltblown fibers. Such a process isdisclosed for example, in U.S. Pat. No. 3,849,241 to Butin et al.Meltblown fibers are microfibers which may be continuous ordiscontinuous, are generally smaller than about 0.6 denier, and aregenerally self bonding when deposited onto a collecting surface.Meltblown fibers used in the present invention are preferablysubstantially continuous in length.

“Member” when used in the singular can have the dual meaning of a singleelement or a plurality of elements.

“Nonwoven” and “nonwoven web” refer to materials and webs of materialwhich are formed without the aid of a textile weaving or knittingprocess.

“Operatively joined,” in reference to the attachment of an elasticmember to another element, means that the elastic member when attachedto or connected to the element, or treated with heat or chemicals, bystretching, or the like, gives the element elastic properties; and withreference to the attachment of a nonelastic member to another element,means that the member and element can be attached in any suitable mannerthat permits or allows them to perform the intended or describedfunction of the composite. The joining, attaching, connecting or thelike can be either directly, such as joining either member directly toan element, or can be indirectly by means of another member disposedbetween the first member and the first element, or can be such that thefirst member is mechanically trapped by adjacent bond points in thefirst element such that the first member causes the composite to exhibitcharacteristics of the first member.

“Permanently bonded” refers to the joining, adhering, connecting,attaching, or the like, of two elements of an absorbent garment suchthat the elements tend to be and remain bonded during normal useconditions of the absorbent garment.

“Polymers” include, but are not limited to, homopolymers, copolymers,such as, for example, block, graft, random and alternating copolymers,terpolymers, etc. and blends and modifications thereof. Furthermore,unless otherwise specifically limited, the term “polymer” shall includeall possible geometrical configurations of the material. Theseconfigurations include, but are not limited to isotactic, syndiotacticand atactic symmetries.

“Pressure” refers to a force per unit area as applied to the wearer'sskin to provide gasketing.

“Spunbonded fibers” refers to small diameter fibers which are formed byextruding molten thermoplastic material as filaments from a plurality offine capillaries of a spinnerette having a circular or otherconfiguration, with the diameter of the extruded filaments then beingrapidly reduced as by, for example, in U.S. Pat. No. 4,340,563 to Appelet al., and U.S. Pat. No. 3,692,618 to Dorschner et al., U.S. Pat. No.3,802,817 to Matsuki et al., U.S. Pat. Nos. 3,338,992 and 3,341,394 toKinney, U.S. Pat. No. 3,502,763 to Hartmann, U.S. Pat. No. 3,502,538 toPetersen, and U.S. Pat. No. 3,542,615 to Dobo et al., each of which isincorporated herein in its entirety by reference. Spunbond fibers arequenched and generally not tacky when they are deposited onto acollecting surface. Spunbond fibers are generally continuous and oftenhave average deniers larger than about 0.3, more particularly, betweenabout 0.6 and 10.

“Stretchable” means that a material can be stretched, without breaking,by at least 50% (to 150% of its initial (unstretched) length) in atleast one direction, suitably by at least 100% (to 200% of its initiallength), desirably by at least 150% (to at least 250% of its initiallength).

“Surface” includes any layer, film, woven, nonwoven, laminate,composite, or the like, whether pervious or impervious to air, gas,and/or liquids.

“Tension” includes a uniaxial force tending to cause the extension of abody or the balancing force within that body resisting the extension.

“Thermoplastic” describes a material that softens when exposed to heatand which substantially returns to a nonsoftened condition when cooledto room temperature.

These terms may be defined with additional language in the remainingportions of the specification.

DETAILED DESCRIPTION OF THE PRESENTLY PREFERRED EMBODIMENTS

The principles of the present invention can be incorporated into anysuitable disposable absorbent article. Examples of such suitablearticles include diapers, training pants, feminine hygiene products,incontinence products, other personal care or health care garments, orthe like. As used herein, the term “incontinence products” includesabsorbent underwear for children, absorbent garments for children oryoung adults with special needs such as autistic children or others withbladder/bowel control problems as a result of physical disabilities, aswell as absorbent garments for incontinent older adults. For ease ofexplanation, the description hereafter will be in terms of a child'straining pant.

Referring to FIG. 1, a disposable absorbent article, such as a trainingpant 20, is illustrated in a partially fastened condition. The trainingpant 20 comprises an absorbent chassis 32 and leg elastic members 58.The absorbent chassis 32 defines a front waist region 22, a back waistregion 24, a crotch region 26 interconnecting the front and back waistregions, an inner surface 28 which is configured to contact the wearer,and an outer surface 30 opposite the inner surface which is configuredto contact the wearer's clothing. With additional reference to FIG. 2,the absorbent chassis 32 also defines a pair of transversely opposedside edges 36 and a pair of longitudinally opposed waist edges, whichare designated front waist edge 38 and back waist edge 39. The frontwaist region 22 is contiguous with the front waist edge 38, and the backwaist region 24 is contiguous with the back waist edge 39.

The illustrated absorbent chassis 32 comprises a somewhat rectangularcomposite structure 33, a pair of transversely opposed front side panels34, and a pair of transversely opposed back side panels 134. Thecomposite structure 33 and side panels 34 and 134 may be integrallyformed or comprise two or more separate elements, as shown in FIG. 2.The illustrated composite structure 33 comprises an outer cover 40, abodyside liner 42 which is connected to the outer cover in a superposedrelation, an absorbent assembly 44 which is located between the outercover and the bodyside liner, and a pair of containment flaps 46. Therectangular composite structure 33 has opposite linear end edges 45 thatform portions of the front and back waist edges 38 and 39, and oppositelinear side edges 47 that form portions of the side edges 36 of theabsorbent chassis 32. Leg openings 52 (FIG. 1) are generally defined byportions of the transversely opposed side edges 36 in the crotch region26. For reference, arrows 48 and 49 depicting the orientation of thelongitudinal axis and the transverse axis, respectively, of the trainingpant 20 are illustrated in FIG. 2.

The leg elastic members 58 are operatively joined to the outer cover 40and/or bodyside liner 42 along the opposite edges 36 and positioned inthe crotch region 26 of the training pant 20 to prevent leakage. Whentension distribution in the leg elastic members 58 is optimized, as inthe present invention, the performance of the leg elastic members 58, interms of comfort, fit and containment, is also optimized. Morespecifically, higher tension provides improved containment while lowertension provides improved comfort. As used herein, the term “crotchregion” refers to the area of the garment 20 located between a wearer'slegs. The areas of the garment 20 located in front of a wearer's legs,behind the wearer's legs and on outer portions of the wearer's legs areconsidered to be away from, or outside of, the crotch region 26.

One example of apparatus for carrying out the invention is showngenerally in FIG. 3. The apparatus 3 includes a pair of pivot arms 18having elastic guide openings 17. Leg elastic members 58 are fed througha strategically placed feed nip 25 (including nip rolls 21 and 23) andthen through the elastic guide openings 17 prior to placement on asubstrate 13 to which the leg elastic members 58 are eventually bondedas the substrate 13 and the leg elastic members 58 pass through a pairof nip rolls 14 and 15. The pivot arms 18 can pivot in a plane eitherparallel (FIG. 7) or perpendicular (FIG. 8) to the substrate 13 as thesubstrate travels through the nip rolls 14 and 15 in a machine direction(indicated by the arrows in FIGS. 3-8). As used herein, the term“machine direction” means the length of a fabric in the direction inwhich it is produced. Alternatively, the pivot arms 18 can pivot in aplane at an angle between parallel and perpendicular to the substrate13.

Each elastic guide opening 17 on the pivot arm 18 preferably guides anindividual leg elastic member 58. As the pivot arm 18 moves the elasticguide openings 17 away from the feed nip 25, tension in the leg elasticmembers 58 increases. As the substrate 13 travels in the machinedirection prior to passing through the pair of nip rolls 14 and 15, theleg elastic members 58 are bonded, also in the machine direction, along,near, or between outer edges 37 of the substrate 13. Leg contours 27 canbe pre-cut along the outer edges 37 of the substrate 13 or may be cutalong the contour of the leg elastic members 58 subsequent to thebonding process. As the elastic guide openings 17 guide the leg elasticmembers 58 toward the crotch region 26, the elastic guide openings 17are moved away from the feed nip 25, thereby causing increased tensionin the leg elastic members 58 as the leg elastic members 58 are bondedto the substrate 13. Conversely, as the elastic guide openings 17 aremoved toward the feed nip 25, the path length decreases, thereby causingdecreased tension in the leg elastic members 58. The regions in whichthe leg elastic members 58 are bonded to the substrate 13 ultimately endup forming the leg openings 52 (FIG. 1).

Another example of apparatus for carrying out the invention is showngenerally in FIG. 4. Like the apparatus 3 in FIG. 3, this apparatus 3includes a pair of pivot arms 18 having elastic guide openings 17, butinstead of just one strategically placed feed nip 25 for each pivot arm18, this apparatus includes a separate, strategically placed feed nip 25(including nip rolls 21 and 23) for each leg elastic member 58. Byhaving separate feed nips 25 for each leg elastic member 58, the tensionprofile of each leg elastic member 58 can be different. As the pivot arm18 moves the elastic guide openings 17 away from each of the feed nips25, tension in the respective leg elastic members 58 increases. Theratio of the leg elastic member path length between the feed nip 25 andthe corresponding elastic guide opening 17 at any given pivot armposition determines the elastic tension profile in the leg elasticmember 58. When the path is decreasing, the respective member 58undergoes less stretching and thereby exhibits less tension. When thepath is increasing, the member 58 undergoes greater stretching andexhibits greater tension. The respective speeds of the feed nips 25 andthe nip rolls 14, 15 also affects elastic tension of the members 58. Thefeed nips 25 can be driven at the same constant speed for uniformtension profiles among the leg elastic members 58, or at differentspeeds for varying tension profiles. Like the apparatus in FIG. 3, asthe elastic guide openings 17 guide the leg elastic members 58 towardthe crotch region 26, the elastic guide openings 17 are moved away fromthe feed nips 25, thereby causing increased tension in the leg elasticmembers 58 as the leg elastic members 58 are bonded to the substrate 13.

Yet another example of apparatus for carrying out the invention is showngenerally in FIG. 5. Like the apparatuses in FIGS. 3 and 4, thisapparatus 3 includes a pair of pivot arms 18 having elastic guideopenings 17 and at least one strategically placed feed nip 25 for eachpivot arm 18. However, this apparatus 3 also features at least onestrategically placed idler roll 12 to change the path length, and thestretching amount, of individual leg elastic members 58. By locating theidler rolls 12 in various positions, the tension profile of each legelastic member 58 can be different. For example, with an idler roll 12on a pivot point 16 of the pivot arm 18, as shown in a position 51 inFIG. 5, the tension in the corresponding leg elastic member 58 will beconstant. With an idler roll 12 closer to the crotch region 26, as shownin a position 53 in FIG. 5, the path length will increase as the pivotarm 18 moves away from the crotch region 26 and thus the tension will behigher in the corresponding leg elastic member 58. In contrast, when theleg elastic member 58 is not wrapped about an idler roll 12, and thefeed nip 25 is located close to the pivot arm 18 when the pivot arm 18is pivoted away from the crotch region 26, as shown in a position 55 inFIG. 5, the path length will decrease as the pivot arm 18 moves awayfrom the crotch region 26, thereby decreasing the tension in the legelastic member 58.

Another arrangement for varying tension along the leg elastic members 58is shown in FIG. 6. The arrangement includes an idler roll 12 on a shaft29 connected to a rotating wheel 31. The elongation, and resultingtension, of the leg elastic member 58 is varied based on the distancefrom the feed nip 25 to the pair of nip rolls 14, 15 and the amount ofdeflection created by the rotating wheel 31. Furthermore, offsetting therotating wheel's 31 axis of rotation or using cams can producenon-symmetrical tension profiles. As explained, the tension ispreferably higher in the crotch region 26 and lower in areas away fromthe crotch region 26. For example, the elongation range can be only 10%elongation in areas away from the crotch region 26 and in a range ofaround 250-300% elongation in the crotch region 26.

A wide variety of elastic materials may be used for the leg elasticmembers 58. As is well known to those skilled in the art, suitableelastic materials include sheets, strands or ribbons of natural rubber,synthetic rubber, or thermoplastic elastomeric polymers. The elasticmaterials can be stretched and adhered to a substrate, adhered to agathered substrate, or adhered to a substrate and then elasticized orshrunk, for example with the application of heat; such that elasticconstrictive forces are imparted to the substrate. A bonding device 11is shown generally in FIGS. 6-8. In one particular embodiment, forexample, the leg elastic members 58 comprise a plurality of dry-spuncoalesced multifilament spandex elastomeric threads sold under the tradename LYCRA® and available from E.I. DuPont de Nemours and Company,Wilmington, Del., U.S.A.

The leg elastic members 58 preferably have elongation of 25-350%, morepreferably about 30-260%, most preferably about 35-200%.

The substrate 13 is preferably the outer cover 40 and desirablycomprises a material that is substantially liquid impermeable, and canbe elastic, stretchable or nonstretchable. The outer cover 40 can be asingle layer of liquid impermeable material, but desirably comprises amulti-layered laminate structure in which at least one of the layers isliquid impermeable. For instance, the outer cover 40 can include aliquid permeable outer layer and a liquid impermeable inner layer thatare suitably joined together by a laminate adhesive (not shown).Suitable laminate adhesives, which can be applied continuously orintermittently as beads, a spray, parallel swirls, or the like, can beobtained from Findley Adhesives, Inc., of Wauwatosa, Wis., U.S.A., orfrom National Starch and Chemical Company, Bridgewater, N.J. U.S.A. Theliquid permeable outer layer can be any suitable material and desirablyone that provides a generally cloth-like texture. One example of such amaterial is a 20 gsm (grams per square meter) spunbond polypropylenenonwoven web. The outer layer may also be made of those materials ofwhich liquid permeable bodyside liner 42 is made. While it is not anecessity for the outer layer to be liquid permeable, it is desired thatit provides a relatively cloth-like texture to the wearer.

The inner layer of the outer cover 40 can be both liquid and vaporimpermeable, or can be liquid impermeable and vapor permeable. The innerlayer is desirably manufactured from a thin plastic film, although otherflexible liquid impermeable materials may also be used. The inner layer,or the liquid impermeable outer cover 40 when a single layer, preventswaste material from wetting articles, such as bedsheets and clothing, aswell as the wearer and caregiver. A suitable liquid impermeable film foruse as a liquid impermeable inner layer, or a single layer liquidimpermeable outer cover 40, is a 0.02 millimeter polyethylene filmcommercially available from Huntsman Packaging of Newport News, Va.,U.S.A. If the outer cover 40 is a single layer of material, it can beembossed and/or matte finished to provide a more cloth-like appearance.As earlier mentioned, the liquid impermeable material can permit vaporsto escape from the interior of the disposable absorbent article, whilestill preventing liquids from passing through the outer cover 40. Asuitable “breathable” material is composed of a microporous polymer filmor a nonwoven fabric that has been coated or otherwise treated to imparta desired level of liquid impermeability. A suitable microporous film isa PMP-1 film material commercially available from Mitsui ToatsuChemicals, Inc., Tokyo, Japan, or an XKO-8044 polyolefin filmcommercially available from 3M Company, Minneapolis, Minn.

As mentioned, the leg elastic members 58 can be bonded to the outercover 40 and/or the bodyside liner 42. FIGS. 6-8 show the leg elasticmembers 58 being bonded to the outer cover 40 and the bodyside liner 42at the same time. In this embodiment, the leg elastic members 58 areessentially sandwiched between the outer cover 40 and the bodyside liner42.

The liquid permeable bodyside liner 42 is illustrated as overlying theouter cover 40 and absorbent assembly 44 (FIG. 2), and may but need nothave the same dimensions as the outer cover 40. The bodyside liner 42 isdesirably compliant, soft feeling, and non-irritating to the child'sskin. Further, the bodyside liner 42 can be less hydrophilic than theabsorbent assembly 44, to present a relatively dry surface to the wearerand permit liquid to readily penetrate through its thickness.

The bodyside liner 42 can be manufactured from a wide selection of webmaterials, such as synthetic fibers (for example, polyester orpolypropylene fibers), natural fibers (for example, wood or cottonfibers), a combination of natural and synthetic fibers, porous foams,reticulated foams, apertured plastic films, or the like. Various wovenand nonwoven fabrics can be used for the bodyside liner 42. For example,the bodyside liner can be composed of a meltblown or spunbonded web ofpolyolefin fibers. The bodyside liner can also be a bonded-carded webcomposed of natural and/or synthetic fibers. The bodyside liner can becomposed of a substantially hydrophobic material, and the hydrophobicmaterial can, optionally, be treated with a surfactant or otherwiseprocessed to impart a desired level of wettability and hydrophilicity.For example, the material can be surface treated with about 0.28 weightpercent of a surfactant commercially available from the Rohm and HaasCo. under the trade designation Triton X-102. The surfactant can beapplied by any conventional means, such as spraying, printing, brushcoating or the like. The surfactant can be applied to the entirebodyside liner 42 or can be selectively applied to particular sectionsof the bodyside liner, such as the medial section along the longitudinalcenterline.

A suitable liquid permeable bodyside liner 42 is a nonwoven bicomponentweb having a basis weight of about 27 gsm. The nonwoven bicomponent canbe a spunbond bicomponent web, or a bonded carded bicomponent web.Suitable bicomponent staple fibers include a polyethylene/polypropylenebicomponent fiber available from CHISSO Corporation, Osaka, Japan. Inthis particular bicomponent fiber, the polypropylene forms the core andthe polyethylene forms the sheath of the fiber. Other fiber orientationsare possible, such as multi-lobe, side-by-side, end-to-end, or the like.While the outer cover 40 and bodyside liner 42 can comprise elastomericmaterials, it can be desirable in some embodiments for the compositestructure to be generally inelastic, where the outer cover, the bodysideliner and the absorbent assembly comprise materials that are generallynot elastomeric.

The absorbent assembly 44 (FIG. 2) is positioned between the outer cover40 and the bodyside liner 42, which components can be joined together byany suitable means, such as adhesives, as is well known in the art. Theabsorbent assembly 44 can be any structure which is generallycompressible, conformable, non-irritating to the child's skin, andcapable of absorbing and retaining liquids and certain body wastes. Theabsorbent assembly 44 can be manufactured in a wide variety of sizes andshapes, and from a wide variety of liquid absorbent materials commonlyused in the art. For example, the absorbent assembly 44 can suitablycomprise a matrix of hydrophilic fibers, such as a web of cellulosicfluff, mixed with particles of a high-absorbency material commonly knownas superabsorbent material. In a particular embodiment, the absorbentassembly 44 comprises a matrix of cellulosic fluff, such as wood pulpfluff, and superabsorbent hydrogel-forming particles. The wood pulpfluff can be exchanged with synthetic, polymeric, meltblown fibers orwith a combination of meltblown fibers and natural fibers. Thesuperabsorbent particles can be substantially homogeneously mixed withthe hydrophilic fibers or can be nonuniformly mixed. The fluff andsuperabsorbent particles can also be selectively placed into desiredzones of the absorbent assembly 44 to better contain and absorb bodyexudates. The concentration of the superabsorbent particles can alsovary through the thickness of the absorbent assembly 44. Alternatively,the absorbent assembly 44 can comprise a laminate of fibrous webs andsuperabsorbent material or other suitable means of maintaining asuperabsorbent material in a localized area.

Suitable superabsorbent materials can be selected from natural,synthetic, and modified natural polymers and materials. Thesuperabsorbent materials can be inorganic materials, such as silicagels, or organic compounds, such as crosslinked polymers. Suitablesuperabsorbent materials are available from various commercial vendors,such as Dow Chemical Company located in Midland, Mich., U.S.A., andStockhausen GmbH & Co. KG, D-47805 Krefeld, Federal Republic of Germany.Typically, a superabsorbent material is capable of absorbing at leastabout 15 times its weight in water, and desirably is capable ofabsorbing more than about 25 times its weight in water.

In one embodiment, the absorbent assembly 44 is generally rectangular inshape, and comprises a blend of wood pulp fluff and superabsorbentmaterial. One preferred type of fluff is identified with the tradedesignation CR1654, available from U.S. Alliance, Childersburg, Ala.,U.S.A., and is a bleached, highly absorbent sulfate wood pulp containingprimarily soft wood fibers. As a general rule, the superabsorbentmaterial is present in the absorbent assembly 44 in an amount of fromabout 0 to about 90 weight percent based on total weight of theabsorbent assembly. The absorbent assembly 44 suitably has a densitywithin the range of about 0.10 to about 0.35 grams per cubic centimeter.The absorbent assembly 44 may or may not be wrapped or encompassed by asuitable tissue wrap that maintains the integrity and/or shape of theabsorbent assembly.

The absorbent chassis 32 can also incorporate other materials that aredesigned primarily to receive, temporarily store, and/or transportliquid along the mutually facing surface with the absorbent assembly 44,thereby maximizing the absorbent capacity of the absorbent assembly. Onesuitable material is referred to as a surge layer (not shown) andcomprises a material having a basis weight of about 50 grams per squaremeter, and including a through-air-bonded-carded web of a homogenousblend of 60 percent 3 denier bicomponent fiber including a polyestercore/polyethylene sheath, commercially available from BASF Corporation,and 40 percent 6 denier polyester fiber, commercially available fromHoechst Celanese Corporation, in Portsmouth, Va., U.S.A.

As noted previously, the illustrated training pant 20 has front and backside panels 34 and 134 disposed on each side of the absorbent chassis 32(FIGS. 1 and 2). These transversely opposed front side panels 34 andtransversely opposed back side panels 134 can be permanently bonded tothe composite structure 33 of the absorbent chassis 32 in the respectivefront and back waist regions 22 and 24, and are releasably attached toone another by a fastening system 80. More particularly, as shown bestin FIG. 2, the front side panels 34 can be permanently bonded to andextend transversely beyond the linear side edges 47 of the compositestructure 33 in the front waist region 22 along attachment lines 66, andthe back side panels 134 can be permanently bonded to and extendtransversely beyond the linear side edges of the composite structure inthe back waist region 24 along attachment lines 66. The side panels 34and 134 may be attached using attachment means known to those skilled inthe art such as adhesive, thermal or ultrasonic bonding. The side panels34 and 134 can also be formed as a portion of a component of thecomposite structure 33, such as the outer cover or the bodyside liner.

Each of the side panels 34 and 134 can include one or more individual,distinct pieces of material. In particular embodiments, for example,each side panel 34 and 134 can include first and second side panelportions that are joined at a seam, with at least one of the portionsincluding an elastomeric material (See FIG. 2). Still alternatively,each individual side panel 34 and 134 can include a single piece ofmaterial which is folded over upon itself along an intermediate foldline (not shown).

The side panels 34 and 134 desirably comprise an elastic materialcapable of stretching in a direction generally parallel to thetransverse axis 49 of the training pant 20. In particular embodiments,the front and back side panels 34 and 134 may each comprise an interiorportion 78 disposed between the distal edge 68 and a respective front orback center panel 35 or 135. In the illustrated embodiment in FIG. 2,the interior portions 78 are disposed between the distal edges 68 andthe side edges 47 of the rectangular composite structure 33. The elasticmaterial of the side panels 34 and 134 can be disposed in the interiorportions 78 to render the side panels elastomeric in a directiongenerally parallel to the transverse axis 49. Most desirably, each sidepanel 34 and 134 is elastomeric from a waist end edge 72 to a leg endedge 70. More specifically, individual samples of side panel material,taken between the waist end edge 72 and the leg end edge 70 parallel tothe transverse axis 49 and having a length from the attachment line 66to the distal edge 68 and a width of about 2 centimeters, are allelastomeric.

Suitable elastic materials, as well as one described process ofincorporating elastic side panels into a training pant, are described inthe following U.S. Pat.: No. 4,940,464 issued Jul. 10, 1990 to VanGompel et al.; U.S. Pat. No. 5,224,405 issued Jul. 6, 1993 to Pohiola;U.S. Pat. No. 5,104,116 issued Apr. 14, 1992 to Pohjola; and U.S. Pat.No. 5,046,272 issued Sep. 10, 1991 to Vogt et al.; all of which areincorporated herein by reference. In particular embodiments, the elasticmaterial comprises a stretch-thermal laminate (STL), a neck-bondedlaminated (NBL), a reversibly necked laminate, or a stretch-bondedlaminate (SBL) material. Methods of making such materials are well knownto those skilled in the art and described in U.S. Pat. No. 4,663,220issued May 5, 1987 to Wisneski et al.; U.S. Pat. No. 5,226,992 issuedJul. 13, 1993 to Morman; and European Patent Application No. EP 0 217032 published on Apr. 8, 1987 in the names of Taylor et al.; all ofwhich are incorporated herein by reference. Alternatively, the sidepanel material may comprise other woven or nonwoven materials, such asthose described above as being suitable for the outer cover 40 orbodyside liner 42, or stretchable but inelastic materials.

The absorbent chassis 32 and the fastening system 80 together define arefastenable pant having a waist opening 50 and a pair of leg openings52. When the fastening system is engaged, it can be appreciated that therefastenable pant includes a pair of elastomeric front side panels 34extending from the waist opening to each leg opening, a pair ofelastomeric back side panels 134 extending from the waist opening toeach leg opening, a pair of refastenable seams 88 (FIG. 1) extendingfrom the waist opening to each leg opening and positioned between theelastomeric front and back side panels, an elastomeric front waistband54 disposed in the front waist region and positioned between the pair ofelastomeric front side panels, an elastomeric back waistband 56 disposedin the back waist region and positioned between the pair of elastomericback side panels, and at least a pair of elastomeric leg members 58which partially encircle each leg opening. More preferably, more thanone elastomeric leg member 58 partially or fully encircles each legopening 52. Each elastomeric leg member 58 extends from adjacent anelastomeric front side panel 34 in the front waist region 22 to adjacentan elastomeric back side panel 134 in the back waist region 24.

As described herein, the various components of the training pant 20 canbe integrally assembled together employing various types of suitableattachment means, such as adhesive, sonic and thermal bonds orcombinations thereof. The resulting product is an absorbent garmenthaving optimized comfort, fit and containment about the leg openings 52.

It will be appreciated that details of the foregoing embodiments, givenfor purposes of illustration, are not to be construed as limiting thescope of this invention. Although only a few exemplary embodiments ofthis invention have been described in detail above, those skilled in theart will readily appreciate that many modifications are possible in theexemplary embodiments without materially departing from the novelteachings and advantages of this invention. Accordingly, all suchmodifications are intended to be included within the scope of thisinvention, which is defined in the following claims and all equivalentsthereto. Further, it is recognized that many embodiments may beconceived that do not achieve all of the advantages of some embodiments,particularly of the preferred embodiments, yet the absence of aparticular advantage shall not be construed to necessarily mean thatsuch an embodiment is outside the scope of the present invention.

We claim:
 1. A method of attaching leg elastics to an absorbent garment,comprising the steps of: using a pivot arm to guide at least two elasticmembers from a feed nip onto a substrate, wherein at least one of theelastic members is wrapped around an idler roll and the idler roll islocated at a pivot point of the pivot arm; and bonding the elasticmembers to the substrate, wherein at least one of the elastic membershas an induced tension profile when bonded to an area of the absorbentgarment.
 2. The method of claim 1 further comprising the step ofsimultaneously bonding the elastic members to the substrate and to asecond layer of material while bonding the elastic members to thesubstrate.
 3. The method of claim 1, further comprising the step ofcapturing the elastic members between the substrate and a second layerwhile bonding the substrate to the second layer.
 4. A method ofattaching leg elastics to an absorbent garment, comprising the steps of:using a pivot arm to guide at least two elastic members from a feed niponto a substrate, wherein at least one of the elastic members is wrappedaround an idler roll and the idler roll is located between a crotch areaand a pivot point of the pivot arm; and bonding the elastic members tothe substrate, wherein at least one of the elastic members has aninduced tension profile when bonded to an area of the absorbent garment.5. The method of claim 4 further comprising the step of simultaneouslybonding the elastic members to the substrate and to a second layer ofmaterial while bonding the elastic members to the substrate.
 6. Themethod of claim 4, further comprising the step of capturing the elasticmembers between the substrate and a second layer while bonding thesubstrate to the second layer.
 7. A method of attaching leg elastics toan absorbent garment, comprising the steps of: using a pivot arm toguide three elastic members from a feed nip onto a substrate, whereintwo of the elastic members are wrapped around two separate idler rolls;and bonding the elastic members to the substrate, wherein at least oneof the elastic members has an induced tension profile when bonded to anarea of the absorbent garment.
 8. The method of claim 7 wherein a firstidler roll is located at a pivot point of the pivot arm and a secondidler roll is located between a crotch area and the pivot point.
 9. Themethod of claim 7 further comprising the step of simultaneously bondingthe elastic members to the substrate and to a second layer of materialwhile bonding the elastic members to the substrate.
 10. The method ofclaim 7, further comprising the step of capturing the elastic membersbetween the substrate and a second layer while bonding the substrate tothe second layer.
 11. A method of attaching leg elastics to an absorbentgarment, comprising the steps of: using a pivot arm to guide at leasttwo elastic members from a feed nip onto a substrate, wherein at leastone of the elastic members is wrapped around an idler roll, and theidler roll is attached to a shaft, and the shaft is attached to arotating wheel; and bonding the elastic members to the substrate,wherein at least one of the elastic members has an induced tensionprofile when bonded to an area of the absorbent garment.
 12. The methodof claim 11 wherein the rotating wheel comprises an offset axis ofrotation.
 13. The method of claim 11 wherein rotation of the rotatingwheel is governed by a cam.
 14. The method of claim 11 furthercomprising the step of simultaneously bonding the elastic members to thesubstrate and to a second layer of material while bonding the elasticmembers to the substrate.
 15. The method of claim 11, further comprisingthe step of capturing the elastic members between the substrate and asecond layer while bonding the substrate to the second layer.